A lot of business has been done this summer, but not all of it has pleased everyone. Here we look at some of the transfers that represent something of a risk for the side that took them on and speculate over whether the club will eventually be left with egg on their face.

Michael Owen: Newcastle to Manchester United. One of the shocks of the summer after the former England striker's management team sent out a 38-page brochure documenting his appeal, to little effect. Injury-prone, out of form and carrying the burden of a high expectation level, United fans were dismayed when Sir Alex Ferguson announced the capture of the former Liverpool poacher on a pay-as-you-play deal. It was not the marquee signing many were expecting to replace the Madrid-bound Cristiano Ronaldo, and there is certainly doubt over whether Owen is still able to cut it at the highest level. On the other hand, he could be good value coming off the bench if he can regain some fitness. Both Fergie and Owen like to gamble, but this is certainly one that could backfire.

Barry Ferguson: Rangers to Birmingham. The former Rangers skipper has been viewed as one of the best players in Scotland over the past few years, but did not have the best of times when he made the move to Blackburn in 2003. He lasted only 16 months after suffering injury and loss of form and has also gained a reputation for falling out with his coaches. His much-publicised indiscretions for the national team after a late-night drinking session also put a question mark over his temperament; but at least he's under the wing of former Gers boss Alex McLeish at St Andrews. Birmingham may already have their hands full with the signing of Lee Bowyer, despite his claims he has turned over a new leaf, but Ferguson could also prove to be difficult.

Roque Santa Cruz: Blackburn to Manchester City. A fee of £18m is a lot to pay for a striker who has only had one successful season in England and spent the majority of 2008-09 on the sidelines through injury. When on his game Santa Cruz is an excellent finisher, but during his eight years at Bayern Munich he managed just over 150 appearances and only 31 goals. He only cost Rovers £3.5m in 2007 and although he netted 19 league goals in his first season for the club, he remains a player who still has something to prove. With Emmanuel Adebayor and Carlos Tevez surely ahead of him in the pecking order, Santa Cruz could soon be labelled an expensive mistake.

Thomas Vermaelen: Ajax to Arsenal. The Dutch league has not provided the English game with the best of recruits in recent years, although the Belgian international will hope to raise the standard. A strong, committed defender who can play at centre-back or on the left side of defence, Vermaelen could be a gamble because he stands at under six feet tall and is likely to be tested in Arsenal's aerially suspect side. The 23-year-old has a footballing education that includes time in the prestigious Ajax academy, but did not make the breakthrough early in his career and has only been playing at the top level since 2006. Arsene Wenger is rarely wrong with his young players, although Philippe Senderos, Igor Stepanovs and Pascal Cygan are examples of his misplaced faith in the defensive department in recent years.

Yuri Zhirkov: CSKA Moscow to Chelsea. The Russian star has impressed at international level, but might find the step-up to the Premier League a difficult one. Aside from where he will play [Ashley Cole will play at left-back and Florent Malouda/Joe Cole in left midfield], Zhirkov has had trouble with the language and has also failed to complete a full pre-season with the club because of work permit issues. The player reportedly cost a fee of around £18m, which seems a lot simply for a backup for the starting XI; but with Roman Abramovich's links to the Moscow club, it's possible they might not have spent anything at all.

Tyrone Mears: Derby County to Burnley. When you have a player who is willing to climb out of a window to escape to a new life in France, it must take a great deal of faith to sign him up. Burnley have taken that risk on 26-year-old defender Mears, who was unhappy with Derby manager Paul Jewell and pulled the stunt in order to fly to Marseille for a trial, where he stayed for the rest of last season. The Clarets picked him up for £500,000, but will be fully aware of the Jamaican international's temperament. Whether they are willing to allow him to put the nickname 'Tye' on the back of his shirt - as he did at Preston - also remains to be seen.

Ross Turnbull: Middlesbrough to Chelsea. Always be wary of a man who says he wants to leave a club to pursue ''regular first-team football'' and then signs for a club like Chelsea, where the hope is remote. The goalkeeper may heed the warning of Steven Sidwell who failed to make an impression at Stamford Bridge, but will also be fairly happy to be paid a good weekly wage to act as backup to Petr Cech and get some experience of the Champions League on his CV. Having spent most of his Boro career on loan at lower division clubs, it is hard to see what persuaded the Blues to sign him up, although he has to be a better option than Hilario.

Ronald Zubar: Marseille to Wolves. It has been quite a fall from grace for the French Under-21 international since he starred for Caen and was linked with a move to Arsenal in the summer of 2006. Several costly mistakes while playing for l'OM have shattered his confidence after he swapped his defensive midfield role for that of centre-back and he opted to move to England to continue his career at Wolves. The player himself has admitted that he's finding the English game "quick" and has the potential to rival fellow countryman Jean Alain Boumsong in the calamity stakes.

Jack Lampe: Harlow Town to West Ham. It's not often that a player jumps straight from Non-League football into the Premier League, but the 17-year-old defender impressed the coaches at Upton Park enough to earn himself a one-year deal after landing a trial. The Hammers are considered to have one of the most productive academy systems in English football, but usually pick up players at a much younger age, allowing them to blossom with help from their own coaching methods. Not likely to push the first-team just yet, Lampe will find the step up tricky, but is only on a short-term contract should he fail to establish himself.

Joey Barton: Newcastle to ??? The combative (for want of another word) midfielder is sure to leave the Magpies this summer as he has burned his bridges with Alan Shearer and pretty much everyone else at the club. With their relegation to the Championship, Barton is keen to return to the top flight with Hull reportedly interested; but any club that takes a punt on the Scouser is sure to have their fingers burnt. Barton does not really come under the tag 'risky', more 'mind blowingly stupid' if he actually does manage to seal a move to another Premier League club. If he doesn't move, Newcastle will have some serious questions to answer.